Furnace



INVENiTOR J. E'. Kennedy W 2 Sheets-Sheet l ATTORNE Il .lllllHHL Ill Jan. 19, 1937.

'EAT ES ainsi FURNACE Joseph E. Kennedy,

New York, N. Y., assigner,

by mesne assignments, to Reconstruction lllinance Corporation,

Philadelphia, Pa., a corporation of the United States 'n Application Claims.

This invention relates to furnaces for boilers, particularly of the water tube type, having an opening or openings in a wall of the furnace through which to fire the furnace and a flue for the outlet of the products of combustion at a point remote from said opening or openings to induce a flow of the heated gases of combustion, means being provided to cause said gases to travel in a circuitous path relative to the boiler tubes to the outlet flue, and it is the principal object of the invention to provide means to prevent thek heavier particles of the products of combustion, such as fly ash or soot, from entering the flue y and passage of the same with the waste products of combustion to and from the stack. n

It is another. object of the invention to increase the efciency of the furnace by the provisio-n of means to divert part of the heated gases into another path of travel to impart additional heat to that portion of the boilerftubes which normally arenot subjected to the transference of the maximum amount of the heat from the hot gases.

In the drawings accompanying and forming a part of this application Figure l is a side elevation of a furnace having the invention embodied therein and indicating the ow of the gases through the separating and collecting pocket induced by a fan.

Figure 2 is a fragmentary View looking at the right of Figure 4.

Figure 3 is a sectional view of therear portion of the furnace showing a modified means for inducing the flow of the gases through the separating and collecting pocket of the furnace by the stack draft.

Figure 4 is a view similar to Figure 3 but showing the means of Figure l for inducing the flow of the heated gases through the separating and co1- lecting pocket adapted to the structure of a vertical water tube type of boiler; and

Figure 5 is a side elevation of a perforated pipe mounted in the separating and collecting pocket through which the gases are withdrawn from said pocket and which prevents withdrawal of the waste material in the pocket.

In carrying out the invention ilustrated in the accompanying drawings, there is provided a furnace arranged with a combustion chamber 6 formed by front, rear and side walls and a oor having air passages I therein for heating and supplying heated air to the feed end of a tube mill 9 for pulverizing fuel, such as coal, delivered therefrom by a fan F through a conduit Il! to a burner II mounted in an opening in the front wall I2 of the furnace. To aid the combustion November 22, 1934, Serial No. 754,253

of the pulverized fuel heated air is supplied to the fuel drawn from the drum by a conduit i3 connected to the connection of the fan with the mill and an air passage l in the front wall i2 o-f the furnace. Atmospheric air is supplied tothe air passages 1 in the furnace walls and floor through inlet passages Ill in the front wall .I2 of the furnace, Figure l.

In the .type of boiler furnace shown in Figures lto 3, the products of combustion and the heated gases resulting from the burning of the pulverized fuel in the combustion chamber 5 rise and circulate between a series of straight water tubes I5 connected andsupported at the ends by a pair of headers I6, Il at the opposite ends of the tubes, header I6 being mounted on the front wall I2 and connected to one end of a steam drum it supported by'thefurnace to extend the entire length thereof.. The header I'iis supportedby a wall I9, constituting theV rear wall of the combustion chamber with the header Il positioned exteriorly of said wall, and connected to the steam drum I8 vat the end opposite to the end connected to the header I6.

The flow of the products of combustion and the heated gases between and around the tubes I5 is induced by the draft of a stack connected by a flue pipe 2l] with a smoke outlet arranged in the rear wall 2I of the furnace in spaced relation to the rear wall I9 of the combustion chamber and forming an elongated chamber 22 in which chamber the header Il is positioned.

To subject the tubes to and effect the maximum transference of heat thereto from the products of combustion and the heated gases, they are induced to circulate between and around said `tubes in a circuitous path by a barile plate Z3 inclining from thetop of the wall lil into the combustion chamber to a point intermediate the ends of said chamber and terminating at the uppermost tier of tubes to direct the rising gases toward the portions of the tubes l5 adjacent the header I6, and a baille plate 24 extending from the lower end of a vertical wall 25 for supporting the steam drum I8 and constituting a wall of the chamber 22, the baffle plate 24 being extended in parallel spaced relation to the header I'I and at an acute angle to the baffle plate 23 and spaced therefrom to divert the passage of the gases below said baffle to the chamber 22.

The arrangement of the baffle plates 23, 24 will direct the ow of the heated gases carrying waste products of combustion in a circuitous path upwardly and over the upper end of the baffle plate 23,. and then downwardly along the in the passage of the gases between the baiile plates l upper surface of said baiiie plate 23 and below the lower end of the baffle plate 24, whereby the eavier gases having the waste products of combustion suspended therein, such as fly ash and soot, will continue to travel in a downward direction and the lighter gases substantially free of ily ash and soot will be caused to rise by the stack draft through the flue pipe 20 and ow into the upper portion of the chamber 22 to enter said ue pipe, as indicated by the arrows.

The heavier gases laden with fly ash and soot will flow in a downward direction and enter a wide mouth entrance to a downwardly extending passage formed by a declining side wall of a receptacle 23, said declining wall being juxtaposed toa corresponding declining portion of the wall I9, as at 21. The opposite wall of the passage is formed by a plate or sheet of material 28 having a bent portion extending in alignment with the header as at 29, to form the wide mouth of the passage, the remaining portion of said wall 28 being supported in parallel spaced relation to the wall 21 by brackets 3U secured to the wall 28 and the opposite side wall of the furnace constituting the ends of the receptacle 25. The receptacle 2li/is mounted in the lower portion of the chamber 22 with the bottom thereof of arcuate form and at the outlet of the passage, the top of the receptacle being closed from the chamber 22 by a plate 3|, forming an ash collecting pocket or pit. A

To separate the fly ash and soot from the gases in the pocket 25, the gases are drawn in an upward direction from the pocket and by the formation of the bottom of the pocket and entering the gases through the downwardly extending passage the gases are expanded within the receptacle thereby effecting a separation of the flyY ash and soot fromthe gases andprecipitation of the same to the bottom of the pocket vby the weight thereof. In the structure disclosed in Figures l, 2 and 4 the flow of the gases through pocket and connected to one end of a pipe 31V mounted in the upper portion of the pocket, the other end of the pipe 31 being closed and the side wall perforated, as shown at 38 in Figure 5, to serve as a baille and prevent removal of -the fly ash and soot with the flow of the gases from the pocket.

The gases are delivered by the fan 32 to and exhausted through the ilue pipe 20. In use with a horizontal water tube type of boiler furnace, as shown in Figure 1, the gases are delivered from the fan casing 33 through a pipe or conduit 39 connected in communication with the outlet of the fan casing and extended through the furnace wall 2| into the chamber 22 with the outlet end thereof terminating in line with the ue opening so that the gases are drawn in to the flue by the stack draft, as illustrated by the arrows.

In Figure 4 the invention is shown applied to a Vertical tube type of boiler furnace wherein a plurality of sections of water tubes 40 are mounted in the furnace to extend in substantially vertical planes with the upper ends of the tubes connected to steam drums, not shown, and the lower ends in communication with a mud drum 4| mounted on the wall IS of the combustion chamber 5 with baflie plates 42 interposed between each section of water tubes to divert the stream of gases from the combustion chamber to the flue pipe ina circuitous path about the water tubes and in a downward direction to adjacent the iiue 2Q, as shown by the arrows. Due to the arrangement of the water tubes adjacent the flue pipe the ash pocket 2t? is arranged with the side walls in substantially vertical and parallel relation to each other, the downwardly extending entrance passage being formed by a plate 43 mounted at the ends ori-the side walls of the furnace and the top closure plate 3| of the pocket to extend obliquely from the inlet to the rear furnace wall adjacent the flue-pipe 29 and into the pocket parallel to a side wall of said pocket. The wall will divert the flow of the ash laden gases into the entrance passage to the pocket. The pocket 26 is mounted in a chamber 44 formed by the bridge wall i9, rear furnace wall 2|, mud drum 4| and the water tubes 40. The outlet of the fan casing 33 is connected to the flue pipe 2B by a pipe or conduit 45 exteriorly of the furnace having an arcuate outlet end 46 mounted in the flue pipe to extend in the direction of flow of the gases in the Vflue pipe due to the arrangement of the water tubes 4t adjacent the flue inlet.

In Figure 3 there is illustrated an arrangement whereby the flow of the gases through the ash separating and collecting pocket 26 is induced by the stack draft by a pipe or conduit 41 having an end portion extended through the furnace wall 2| connected to the perforated separating pipe 3l,

pipe 2) similar to the Whether the ow of the gases through the ash pocket 26 is induced by a fan or by the stack draft will depend on the strength of the draft in each particular structure of furnace, and the use of the stack draft alone may be used in any type of furnace and not only in a horizontal water tube boiler furnace, as illustrated in Figure V3. The use of the fan 31 to induce the iiow of the gases through the ash pocket will also increase the force of the dra'ft in the furnace and to use the fan 31 exclusively for creating a draft in the furnace or to induce and regulate the ow of the gases through the ash pocket 26, a damper is arranged in the pipe 36, as indicated in dotted lines at 49.

In all the arrangements of the ash pocket 26 the ashes are removed through a clean out opening 5B arranged in the arcuate bottom wall of the pocket having a closure 5| slidably mounted on the exterior of the pocket, and the ashes are removed from the furnace through an opening 53 in the furnace wall 2| having a closure 54.

It will also be noted that the ow of the gases laden with the heavy waste products of combustion to the separating and collecting pocket will pass a portion of the water tubes, as at 50, that will not ordinarily be alTected by the flow of the gases from the combustion chamber to the outlet flue and whereby there will be a maximum transference of heat to said portion of the tubes from such heated gases and thereby materially increase the efficiency of the furnace.

While I have illustrated one embodiment of my invention, it will be obvious that various modifications may be made in construction and arrange- 'mentof parts, and that portions of the invention may be used without others and come lwithin thev scope of the invention.

Having thus described my invention, I claim:

l.' In a furnace, a combustion chamber, a smoke outlet spaced from the combustion chamber, means to arrange the furnace with a downward and upward sinuous passage for the gases from the combustion chamber to the smoke outlet, a receptacle mounted in the space between the combustion chamber and smoke outlet, a plate mounted in the receptacle to form with a side wall of the receptacle a passage with the inlet opening to a lower portion of the sinuous passage for the gases and the outlet opening to the bottom of the receptacle, and a perforated pipe mounted in the upper portion of the receptacle having an outlet in communication with and adapted to conduct the .gases from the receptacle to the smoke outlet, said pipe in conjunction with the yreceptacle passage effecting a separation of ash and soot from the gases in their passage through the receptacle to said pipe.

2. In a furnace as claimed in claim 1, a fan connectedto the outlet of the perforated pipe operative to induce the flow of the gases from the furnace into the receptacle and through the perforated pipe to the smoke outlet.

3. In a water tube boiler furnace having a smoke outlet, a series of water tubes connected with rear and front headers, means in the furnace to cause the gases to pass in an upward and downward sinuous passage between the water tubes from the combustio-n chamber to the smoke outlet, a receptacle, a plate mounted in the receptacle to form with a side wall of the receptacle a passage leading from the top to the bottom of the receptacle with the inlet in the upper end opening to the sinuous passage for the gases in the furnace below the water tubes and the outlet at the lower end opening tothe bottom of the receptacle for the flow of gases therethrough from the furnace and said passage being of less area than the receptacle and the passage of the gases therethrough into the receptacle effecting an expansion and separation of ash and soot from the gases, a conduit leading from the upper portion of the receptacle to the smoke outlet for the passage of gases from the receptacle to the smoke outlet, and a damper in said conduit to regulate the flow of gases therethrough from the receptacle to the smoke outlet.

4. In a furnace having a combustion chamber and a smoke outlet spaced from the combustion chamber, means in the furnace to cause the gases to travel in a sinuous passage from the combustion chamber to the smoke outlet, a casing having a chamber therein, a plate mounted in the receptacle to form with a side wall of the receptacle a passage the inlet of which passage opens through the top of the chamber to the sinuous passage for the gases from the combustion chamber to the smoke outlet and the outlet opening to the bottom of the casing chamber for the flow of gases from the furnace into and through said casing chamber, means communicating with the smoke outlet and casing chamber to induce a flow of gases from the furnace into and through the casing chamber and delivery of said gases to the smoke outlet, the passage of the gases through the casing chamber effecting a separation of ash and soot from the gases therein, and means to control the flow of gases through the casing chamber to the smoke outlet.

""5. `In a water tube boiler furnace having a smoke outlet, a series of water tubes connected with front andv rear headers, means in the furnace to cause the gases to travel in an upward and downward sinuous passage between the water tubes from the combustion chamber to the smoke outlet, a casing having' a chamber therein with an inlet in communication with said sinuous passage between the water tubes and smoke outlet for a flow of gases from the furnace into said casing chamber, and said casing chamber arranged with means to separate and precipitate ash and soot from the gases therein, regulatable means to connect the casing chamber with the smoke outlet, and means to induce the fiow of thegases into and through the' casing chamber to the smoke outlet.

6. In a water tube boiler furnace having front,

rear=and rside walls with smoke outlet means through the `upper portion of the rear wall and a wall extended upwardfrom the furnace floor in spaced relation to the rear furnace wall and constituting the rear wall of the combustion chamber of the furnace, water tubes above the combustion chamber extending from the front to the rear furnace walls connected with a front header disposed above the front furnace wall and with a rear header disposed above the space between the rear walls of the furnace and combustion chamber, means to provide a circuitous passage for the gases rising from the combustion chamber over the water tubes to the smoke outlet means, a receptacle between the rear walls of the furnace and combustion chamber having an inlet in the top opening to the furnace, means to connect the top of said receptacle with and induce a flow of gases from the circuitous passage into and through the receptacle from the furnace to the smoke outlet means, and a plate co-operating with the rear water tube header to connect the receptacle inlet with the circuitous passage in the furnace to provide a passage in the receptacle from the inlet to the bottom of the receptacle, the gases passing through said passage into the receptacle expanding in the receptacle and thereby effecting a separation of the ash .and soot from the gases flowing into and through the receptacle.

7. In a furnace having a combustion chamber and a stack outlet spaced from the combustion chamber, bafes in the furnace arranged to provide a sinuous passage for the gases from the combustion chamber to the smoke outlet, a receptacle in the space between the combustion chamber and stack outlet arranged with means to provide a passage in the receptacle having an inlet opening through the top of the receptacle to an intermediate portion of the sinuous passage in the furnace and the outlet opening to the bottom of the receptacle, and means to connect the upper portion of the receptacle in communication with the stack outlet and induce a flow of gases from the furnace through the passage into and through the receptacle to the stack outlet and separate heavy particles from the gases and retain the same in the receptacle.

8. In a furnace, a combustion chamber, a smoke outlet from the furnace spaced from the combustion chamber, means arranged to provide a sinuous passage in the furnace for the fiow of the gases from the combustion chamber to the smoke outlet, a receptacle at the rear of the combustion chamber, means mounted in the receptacle to form with a wall thereof an elongated passage in the receptacle having the inlet opening to a lower portion of the sinuous passage in the furnace between the combustion chamber and smoke outlet and the outlet of said passage opening to the bottom of the receptacle, and means for connecting and inducing the ow of gases to and through the receptacle to the smoke outlet comprising a pipe connected at one end in communication with the upper portion of the receptacle and the opposite end opening to the smoke outlet.

9. In a furnace, a combustion chamber, a smoke outlet from the furnace spaced from the combustion chamberpmeans arranged to provide a sinuous passage in the furnace for the outlet of the gases from the combustion chamber to the smoke outlet, a receptacle at the rear of the combustion chamber, means mounted in the receptacle and forming with a wall thereof an elongated passage in the receptacle having the inlet opening to a lower portion of the sinuous passage in the furnace between the combustion chamber and smoke outlet and the outlet of said passage opening to the bottom of the receptacle, and a fan connected in communication with the upper portion of the receptacle and the smoke outletV to induce. a-iiow `oi gases ,to and through the Areceptacle to the smoke outlet.

10. In a furnace, a combustion chamber, a. smoke outlet from the furnace spaced from the combustion' chamber, means arranged to provide a sinuous passage in the furnace for the flow of the gases fromthe combustion chamber to the smoke outlet, a receptacle at the rear of the combustion chamber, means mounted in the receptacle to form with the wall thereof an elongated passage in the receptacle having the inlet opening to the lower portion of the sinuous passage in the furnace between the combustion chamber and the smoke outlet and the outlet of said passage opening' to the bottom of the receptacle, means for connecting the receptacle ,with the smoke outlet and induce aflow of gases from the furnace through the passage into and through the receptacle to the smoke outlet, and adjustable means mounted in the means for connecting the receptacle with the smokeroutlet to regulate the connection of the receptacle with the smoke outlet and iiow of gases through the receptacle. Y

JOSEPH E. KENNEDY. 

